Hansard

I thank colleagues from across the chamber for supporting my motion on protecting Scotland’s rivers. My thanks go, too, to Susan Cooksley from the James Hutton Institute, and Craig Macadam and Rebecca Lewis from Buglife for their support in developing the motion. I also commend the many organisations, some of which are referred to in the motion, and individuals who are working hard to protect our wonderful rivers.

As the motion says, our rivers provide Scotland with stunning landscapes and a huge ecosystem of animals, plants and micro-organisms. They flow from our mountains through our glens, they cross our lowlands and they eventually reach the sea. They are the lifeblood of the landscape and are central to Scotland’s brand, economy and sense of place. However, our rivers are under threat, causing them to become more nature depleted than ever before. Flooding is among the largest threats to Scotland’s rivers, eroding the soil from riverbanks and leading to the destruction of habitats.

As the nature champion for the freshwater pearl mussel, I draw members’ attention to the findings of a 2023 NatureScot report centred on freshwater pearl mussels in the River Dee, which runs through my constituency of Aberdeen South and North Kincardine. The report found that the mussel population had decreased by 90 per cent since 2002. For context, more than 1 million freshwater pearl mussels have been lost, which is a truly shocking amount. The report links that decline to the devastating effects of storm Frank in 2015, which caused significant damage to the river bed, rendering it largely unsuitable for mussels. The River Dee is the only river in Scotland to have suffered such a loss. However, our other rivers are similarly vulnerable.

Although significant flooding is a natural and important feature of a river’s hydrology, flood events used to be infrequent, occurring once in a generation. However, there has been a marked increase in the frequency and severity of floods. The same climate pressures that have led to increased flooding also contribute to water scarcity. During periods of drought, our rivers face severe stress. Reduced water levels, rising temperatures and lower oxygen concentrations combine to create harsh conditions for aquatic life. Additionally, pollutants become more concentrated, further degrading water quality. Although all river species are affected, those that are unable to move, such as mussels, are especially vulnerable.

Water scarcity poses a significant risk to Scotland’s rivers, and the risk will grow as climate change accelerates. Just this year, we experienced our driest spring in 60 years, leaving the entirety of Scotland in varying degrees of drought. Rivers used to be able to rely on snowmelt from the mountains to ensure healthy and cooler water levels. However, due to rising temperatures, that is no longer the case. In summer 2018, it is estimated that 70 per cent of Scotland’s rivers experienced temperatures exceeding 23°C. That figure is notable, as it is the temperature at which Atlantic salmon exhibit thermal stress. It is of concern that the Met Office is projecting that similar conditions could impact our rivers every other year by 2050.

Many of our native species require colder river temperatures in which to live. As such, riparian woodland expansion not only benefits biodiversity and the overall habitat but provides much-needed shade to cool our river waters. I commend the River Dee Trust on its work to expand riparian woodland along the river. That work is absolutely vital to the long-term survival of Dee salmon. Salmon, of course, host pearl mussel larvae until they drop off, sink to the river bed and grow into mussels. Many such projects are already supported through, for example, the Scottish Government’s nature restoration fund; the Riverwoods initiative, which co-ordinates nationwide efforts to restore and protect Scotland’s riverbank woodlands; and the peatland action project, which supports the improvement of degraded peatlands across Scotland. The Natural Environment (Scotland) Bill offers an opportunity to establish a legal framework for biodiversity targets, including in the freshwater ecosystem. However, an even greater scale of action is urgently needed.

My call to action is to build on the work that is already under way and to develop a national approach to make our rivers and freshwater populations even more resilient to extreme climate events. Further still, considerations could be given to land management policies that drive evidence-based, prioritised catchment-scale management, development of riparian woodland and the diversification of upland land use to protect our natural water stores.

I believe that that aligns with the recently published Scottish Environment LINK report, entitled “Restoring Scotland’s Waters”, which highlights 10 key areas for improving Scotland’s freshwater ecosystems, including adopting a source-to-sea approach, restoring natural processes to rivers and lochs and tackling invasive non-native species. I look forward to hearing the cabinet secretary’s response to that proposition.

The future of our rivers depends on the actions that we take today. The devastating decline of freshwater pearl mussels in the River Dee serves as a stark indicator that change is urgently needed. Our rivers are crucial to sustaining Scotland’s unique wildlife and biodiversity. More than that, they are central to Scotland’s brand, economy and sense of place.

I again thank members for their support in lodging the motion for debate. I very much look forward to hearing colleagues’ contributions.